With the advent of networking era, information sharing speed is accelerated, so is popularization and advancement of information technology. Regardless of the fields of computer, communication and consumer-electronics, diversified products thereof have deeply penetrated into daily life of all walks of life.
Among them, portable data storage devices formed by combining a data transmission interface and non-volatile memory, such as flash memory, are widespread and commonplace nowadays. Besides, keeping abreast with the fast development of fabrication technique in semiconductor industry, devices associated with flash drives, portable external hard disks or other flash memories tend to decrease in size while providing higher portability. The storage capacities of those devices can easily reach the level of Tera bytes, and are still climbing up. As a result, such devices are favored by consumers in terms of the use for data sharing.
As far as flash drives are concerned, each of them is usually equipped with a USB plug (USB device structure) to be plugged in a USB socket of a computer for data access.
However, regular USB device structure has a tiny surface that is inconvenient to be printed with texts and/or graphs thereon. Hence, vendors manufacture USB device structure having the size of a business card so as to enlarge their sizes and facilitate printing and advertising with the enlarged area.
With reference to FIG. 1, disclosed in Taiwanese Patent Issue Number M328060, a USB device structure has a flat body 60, a memory module mounted inside the body 60, a signal connection line 61 of the memory module and a USB type A male connector 62. The body 60 has a first panel 601 and a second panel 602. The first panel 601 has a cable slot 603 and a plug slot 604. The cable slot 603 is narrow and formed in the first panel 601. The plug slot 604 is rectangular and formed in the first panel, communicates with the cable slot 603, and serves to accommodate the USB type A male connector.
Additionally, with reference to FIGS. 2A and 2B, the diagrams are shown in unit of millimeter. In accordance with the standard of a type A connector 70 of USB transmission interface, the thickness of a metal frame 71 of the male connector 70 is 4.5 mm±0.1 mm. A part of the thickness 72 serves to accommodate multiple metal contacts 83 and their bearer 84 of a female connector 80. A thickness 82 inside the female connector 80 serves to accommodate multiple metal contacts 73 and their bearer 74. In other words, a thickness from the bearer 84 of the female connector 80 to an outer frame 81 of the female connector 80 is equal to a minimal thickness of the male connector 70. Accordingly, due to the limitation of the standard specifications, the thickness of the male connector 70 fails to be thinner, thus limiting the applicability of USB device structure.
Although the well-developed fabrication technique of semiconductor industry significantly diminishes the size of memory module and lowers the production cost, limited by the standard specifications of USB connectors, the sizes of USB device structure fail to be thinner and thus limit their applications in the aspects of advertisement and promotion. Likewise, the USB device structure is unable to be applied to credit cards, debit cards, personal ID card (approximately 1.7 to 1.9 mm in thickness), regular business card (approximately 0.3 to 0.5 mm in thickness) or promotion card board (approximately 1.8 to 2.0 mm in thickness). As a consequence, the USB device structure have their limitation in applications to content of merchandise, event propaganda and website navigation.
Moreover, as a result of the thickness issue, the USB device structure are not easy to be properly received within stationeries, a document holders or business card holders having limited space.